From 6dabd46a2d8ec341113cb3b257bd6548442a1ea5 Mon Sep 17 00:00:00 2001
From: Jan Schmidt <jan@centricular.com>
Date: Mon, 4 May 2015 18:17:21 +1000
Subject: [PATCH] videoaggregator: Catch errors, and allow sub-class to return
 NULL from get_output_buffer()

A return value of GST_FLOW_OK with a NULL buffer from get_output_buffer()
means the sub-class doesn't want to produce an output buffer, so
skip it.

If gst_videoaggregator_do_aggregate() generates an error, make sure
to propagate it - don't just ignore and discard the error by
over-writing it with the gst_pad_push() result.
---
 gst-libs/gst/video/gstvideoaggregator.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/gst-libs/gst/video/gstvideoaggregator.c b/gst-libs/gst/video/gstvideoaggregator.c
index d31690fcf1..2f720f382e 100644
--- a/gst-libs/gst/video/gstvideoaggregator.c
+++ b/gst-libs/gst/video/gstvideoaggregator.c
@@ -1198,6 +1198,10 @@ gst_videoaggregator_do_aggregate (GstVideoAggregator * vagg,
         gst_flow_get_name (ret));
     return ret;
   }
+  if (*outbuf == NULL) {
+    /* sub-class doesn't want to generate output right now */
+    return GST_FLOW_OK;
+  }
 
   GST_BUFFER_TIMESTAMP (*outbuf) = output_start_time;
   GST_BUFFER_DURATION (*outbuf) = output_end_time - output_start_time;
@@ -1369,6 +1373,8 @@ gst_videoaggregator_aggregate (GstAggregator * agg, gboolean timeout)
   if (jitter <= 0) {
     ret = gst_videoaggregator_do_aggregate (vagg, output_start_time,
         output_end_time, &outbuf);
+    if (ret != GST_FLOW_OK)
+      goto done;
     vagg->priv->qos_processed++;
   } else {
     GstMessage *msg;
@@ -1405,6 +1411,8 @@ gst_videoaggregator_aggregate (GstAggregator * agg, gboolean timeout)
   goto done_unlocked;
 
 done:
+  if (outbuf)
+    gst_buffer_unref (outbuf);
   GST_VIDEO_AGGREGATOR_UNLOCK (vagg);
 
 done_unlocked: